scholarly journals Palladium-Supported Zirconia-Based Catalytic Degradation of Rhodamine-B Dye from Wastewater

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1522
Author(s):  
Salma Jabeen ◽  
Muhammad Sufaid Khan ◽  
Rozina Khattak ◽  
Ivar Zekker ◽  
Juris Burlakovs ◽  
...  

The catalytic activity of Pd/ZrO2 was studied in terms of the degradation of rhodamine-B dye in the presence of hydrogen peroxide. Pd/ZrO2 was prepared by impregnation method, calcined at 750 °C and characterized by XRD, SEM and EDX. The catalyst showed good catalytic activity for dye degradation at 333 K, using 0.05 g of the catalyst during 5 h. The reaction kinetics followed the pseudo-first order kinetics. The Freundlich, Langmuir and Temkin isotherms were applied to the data and the best fit was obtained with Freundlich isotherm. Thermodynamic parameters, like ΔH, ΔG and ΔS were also calculated. The negative values of ΔH (−291.406 KJ/mol) and Gibbs free energy (ΔG) showed the exothermic and spontaneous nature of the process. The positive ΔS (0.04832 KJ/mol K) value showed suitable affinity of catalyst for dye degradation. The catalyst was very stable, active and was easily separated from the reaction mixture by filtration. It can be concluded from the results that the prepared catalyst could be effectively used in dyes degradation/removal from water subjected to further validation and use for various dyes.

2021 ◽  
Vol 02 ◽  
Author(s):  
Amanda Carolina Soares Jucá ◽  
Francisco Henrique Pereira Lopes ◽  
Herbert Vieira Silva-Júnior ◽  
Lara Kelly Ribeiro Silva ◽  
Elson Longo ◽  
...  

Aims: In the present study, we investigate the photocatalytic properties of α-Ag2WO4 nanocrystals-modified Palygorskite (PAL) clay synthesized by the impregnation method. The PAL clay was chemically purified and heat-treated (500 ºC for 2 h), which served as an excellent supporting matrix for loading α-Ag2WO4(α-AWO) nanocrystals. Background: Water contamination is one of the most serious problems affecting human health, ecosystem survival, and the economic growth of societies. Industrial effluents, such as textile dyes, when not treated and improperly discharged into water resources are considered the main cause of water pollution. Thus the scientific community has been developing effective remediation technologies based on advanced oxidative processes to reduce the harmful effects of these organic pollutants. Objective: Improve the photocatalytic activity of PAL clay with α-AWO nanocrystals to degradation of Rhodamine B (RhB) dye. Methods: We purify and heat-treated the PAL clay, synthesize nanocrystals ofα-AWO nanocrystals and modify PAL clay with 30% α-AWO nanocrystals by the impregnation method. The modified PAL clay was able to improve RhB dye degradation. The materials were characterized by XRD, RAMAN,FE-SEM, FT-IR, XRF, etc. The samples were used as photocatalysts under UV-C lamps for the degradation of RhB dye in order to analyze its catalytic performances. Results: ThePAL clay modified with 30% α-AWO nanocrystals showed a catalytic efficiency of 79%, and degradation kinetics about 16 times higher when compared to PAL-500 only purified and heat-treated at 500 ºC. In this way, this PAL-modified is an alternative as a low-cost photocatalyst for the degradation of RhB dye. Conclusion: Ultraviolet-Visiblespectra revealed that our materials have opticalband gap energies controlled by indirect and direct electronic transitions and suitable to be activated under ultraviolet illumination. The adequate amount (30 wt.%) of α-Ag2WO4 nanocrystals added to PAL brought significant improvement of photocatalytic activity for the degradation of rhodamine B. Finally, a photocatalytic mechanism was proposed in detail.


2019 ◽  
Vol 67 (6) ◽  
pp. 1016-1023 ◽  
Author(s):  
Hong‐jian Zhao ◽  
Ren‐Jang Wu ◽  
Xu‐Cheng Wang ◽  
Yu‐min An ◽  
Wen‐Xia Zhao ◽  
...  

2018 ◽  
Vol 26 (6) ◽  
pp. 1264-1269 ◽  
Author(s):  
Muhammad Saeed ◽  
Majid Muneer ◽  
Nida Mumtaz ◽  
Mohsin Siddique ◽  
Nadia Akram ◽  
...  

2011 ◽  
Vol 239-242 ◽  
pp. 182-185 ◽  
Author(s):  
Ying Jie Zhang ◽  
Guo Rui Liu ◽  
Da Peng Li ◽  
Yue Xiao Tian ◽  
Li Zhang ◽  
...  

Solid super acid (S2O82-/FexOy-CuOx) was prepared and used as a heterogeneous Fenton-like catalyst to decompose H2O2for the degradation of refractory dye Orange IV in water. The factors that affected the degradation of Orange IV were discussed in this heterogeneous Fenton-like system. The catalytic activity of S2O82-/FexOy-CuOxwas evaluated by the degradation of Orange IV and the decomposition of H2O2. The results show that the catalyst S2O82-/FexOy-CuOxhas a good catalytic activity. The reaction follows pseudo-first-order kinetics; the reaction rate constant has a good relationship with the concentration of H2O2. The degradation rate of Orange IV and the decomposition rate of H2O2increase with the increase of temperature and the dosage of catalyst whereas it decreases with the increase of the initial concentration of Orange IV and the initial pH.


Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 974
Author(s):  
Piotr Zawadzki ◽  
Małgorzata Deska

In this study, the effectiveness of a rhodamine B (RhB) dye degradation process at a concentration of 20 mg/L in different advanced oxidation processes—H2O2/UV, O3/UV and PDS/UV—has been studied. The use of UV in a photo-assisted ozonation process (O3/UV) proved to be the most effective method of RhB decolorization (90% after 30 min at dye concentration of 100 mg/L). The addition of sulfate radical precursors (sodium persulfate, PDS) to the reaction environment did not give satisfactory effects (17% after 30 min), compared to the PDS/UV system (70% after 30 min). No rhodamine B decolorization was observed using hydrogen peroxide as a sole reagent, whereas an effect on the degree of RhB degradation was observed when UV rays strike the sample with H2O2 (33% after 30 min). The rhodamine B degradation process followed the pseudo-first-order kinetics model. The combined PDS/O3/UV process has shown 60% color removal after 30 min of reaction time at an initial dye concentration of 100 mg/L. A similar effectiveness was obtained by only applying ozone or UV-activated persulfate, but at a concentration 2–5 times lower (20 mg/L). The results indicated that the combined PDS/O3/UV process is a promising method for high RhB concentrations (50–100 mg/L) comparing to other alternative advanced oxidation processes.


2021 ◽  
Author(s):  
Y. AlIssa ◽  
S. T. Sajjadian ◽  
S. M. Hamidi ◽  
S. Sadeghi ◽  
M. R. Nabid

Abstract The combination of the properties of nanostructures, photocatalytic semiconductors, and plasmonic materials can significantly contribute to improving the performance of the entire photocatalysis process. We tried to produce a unique catalyst by combining these three properties. We have produced a two-dimensional nanostructure which was then coated with gold as a plasmonic material followed by SrTiO3 as semiconductor material. The result was the production of the first catalyst of its kind made in this way, which offered notable results. The degradation ability of the sample was examined with different degrees of pH of rhodamine B dye, where we achieved the highest degradation, 16%, at pH10.


2015 ◽  
Vol 351 ◽  
pp. 104-112 ◽  
Author(s):  
Fei Tian ◽  
Zhansheng Wu ◽  
Qiuyu Chen ◽  
Yujun Yan ◽  
Giancarlo Cravotto ◽  
...  

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